Line Input Gain; Instrument Input; Z In (Input Impedance); Filter - Focusrite ISA Two User Manual

Channel Controls...
+48V
Pressing the +48V button applies phantom power to the Mic input XLR. This switch does not affect
the Line or Instrument inputs.
If you are unsure whether your microphone requires phantom power please refer to its handbook. Certain
microphones (most notably ribbon and unbalanced mics) could be damaged by applying phantom power.
Note that the +48V phantom buttons will always be in the off state after power up.

Line Input Gain

The Gain switch adjusts the gain between -20 dB and +10 dB in 10 dB steps. Continuous gain
adjustment of up to 20 dB can be added using the Trim control.

Instrument Input

The Instrument inputs are accessed via standard 1/4" mono jacks on the front panel. The level is set
using the Trim control only and is continuously adjustable from +10 dB to +40 dB.

Z In (Input Impedance)

With the Mic input selected, pressing the Z In button steps through the four
transformer preamp input impedance options. The values are shown in the
table.
For additional information on impedance selection see Appendix 2, "Preamp Input
Impedance" on page 10.
With the Instrument input selected, pressing the switch toggles between High
(guitar pickups) and Low (vintage/high Z-out equipment) settings, as shown
in the lower table.
The Line input impedance is fixed at 10 kΩ and is not affected by the Z In
switch.

Filter

Pressing the Filter button inserts the 18 dB/octave high-pass filter into channel path; it is applied
to whichever input is selected. The High Pass Filter control allows the roll-off frequency to be set
within the range 16 Hz to 420 Hz.
The filter is useful for removing any unwanted low frequencies, eg., rumble transmitted through floor mounted
mic stands, etc.

Insert

Pressing Insert places the Insert Return signal into the channel path before the Output connector,
allowing the inclusion of external effects units.
The Insert Send output is always available and is post the input Gain, Phase and Filter controls.
5
Low
600 Ω
1.4 kΩ
ISA 110
Med 2.4 kΩ
High 6.8 kΩ
Mic Impedance
Low
470 kΩ
High 2.4 MΩ
Instrument Impedance